<html>
  <head>
    <meta charset="utf-8" />
    <link type="text/css" href="./css/style.css" rel="stylesheet" />
    <script src="https://www.jq22.com/jquery/jquery-1.10.2.js"></script>

    <style type="text/css">
      /* body {
        background: #000;
        position: relative;
      } */

      html,
      body {
        position: relative;
        width: 100%;
        height: 100%;
        margin: 0;
        padding: 0;
        overflow: hidden;
      }

      .container {
        width: 100%;
        height: 100%;
        margin: 0;
        padding: 0;
        z-index: 9999 !important;
      }
      #music {
        z-index: 999999 !important;
        position: fixed;
        top: 0;
        left: 0;
      }
      .canvas {
        bottom: 0;
        left: 0;
        position: absolute;
        right: 0;
        top: 0;
      }

      #wrapper {
        display: flex;
        height: 100vh;
        width: 100vw;
      }

      .content {
        background: rgba(0, 0, 0, 0.8);
        color: #f4f4f4;
        height: 200px;
        margin: auto;
        padding: 2rem;
        position: relative;
        overflow: hidden;
        width: 400px;
        z-index: 1;
      }

      a {
        color: #999;
      }
    </style>
  </head>

  <body>
    <div id="wrapper">
      <!-- <div class="content">
            In photography, is the aesthetic quality of the blur produced in the out-of-focus parts of an image produced by a lens. Bokeh has been defined as "the way the lens renders out-of-focus points of light". Differences in lens aberrations and aperture shape
            cause some lens designs to blur the image in a way that is pleasing to the eye, while others produce blurring that is unpleasant or distracting��"good" and "bad" bokeh, respectively. Bokeh occurs for parts of the scene that lie outside the
            depth of field.
        </div> -->

      <audio
        src="sd.mp3"
        controls="controls"
        autoplay="autoplay"
        loop="loop"
        id="music"
      ></audio>
      <div id="jsi-snow-container" class="container"></div>
      <div class="box">
        <ul class="minbox">
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
        </ul>
        <ol class="maxbox">
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
        </ol>
      </div>
    </div>
  </body>
  <script>
    "use strict";

    var parentEl;
    var c1;
    var c2;
    var ctx1;
    var ctx2;
    var canvasWidth;
    var canvasHeight;
    var sizeBase;
    var count;
    var hue;
    var options;
    var parts = [];

    /**
     * Helper function to create a HTML5 canvas and add a class to it
     * @return {[canvas]}
     */
    function createCanvas() {
      var canvas = document.createElement("canvas");
      canvas.classList.add("canvas");
      if (
        navigator.userAgent.match(
          /(phone|pod|iPhone|iPod|ios|Android|Mobile|BlackBerry|IEMobile|MQQBrowser|JUC|Fennec|wOSBrowser|BrowserNG|WebOS|Symbian|Windows Phone)/i
        )
      ) {
        var box = document.querySelectorAll(".box")[0];
        box.style.left = "-42%";
      }
      return canvas;
    }

    /**
     * Helper function to generate a random value between min and max
     * @param  {[int]} min [min value]
     * @param  {[int]} max [max value]
     * @return {[int]}     [random value between min and max]
     */
    function rand(min, max) {
      return Math.random() * (max - min) + min;
    }

    /**
     * Helper function to generate hsla string for canvas 2d context
     * @param  {[int]} h [hue]
     * @param  {[int]} s [saturation]
     * @param  {[int]} l [lightness]
     * @param  {[float]} a [alpha]
     * @return {[string]}
     */
    function hsla(h, s, l, a) {
      return "hsla(" + h + "," + s + "%," + l + "%," + a + ")";
    }

    /**
     * Helper function used for debouncing
     * @param  {[Function]} fn [function to debounce]
     * @param  {[int]} delay [debounce delay]
     */
    function debounce(fn, delay) {
      var timer = null;
      return function () {
        var context = this;
        var args = arguments;

        clearTimeout(timer);
        timer = setTimeout(function () {
          fn.apply(context, args);
        }, delay);
      };
    }

    function createAnimation() {
      sizeBase = canvasWidth + canvasHeight;
      count = Math.floor(sizeBase * 0.3);
      hue = rand(0, 360);
      options = {
        radiusMin: 1,
        radiusMax: sizeBase * 0.04,
        blurMin: 10,
        blurMax: sizeBase * 0.04,
        hueMin: hue,
        hueMax: hue + 100,
        saturationMin: 10,
        saturationMax: 70,
        lightnessMin: 20,
        lightnessMax: 50,
        alphaMin: 0.1,
        alphaMax: 0.5,
      };

      ctx1.clearRect(0, 0, canvasWidth, canvasHeight);
      ctx1.globalCompositeOperation = "lighter";

      while (count--) {
        //init variables for canvas context
        var radius = rand(options.radiusMin, options.radiusMax);
        var blur = rand(options.blurMin, options.blurMax);
        var x = rand(0, canvasWidth);
        var y = rand(0, canvasHeight);
        var hue = rand(options.hueMin, options.hueMax);
        var saturation = rand(options.saturationMin, options.saturationMax);
        var lightness = rand(options.lightnessMin, options.lightnessMax);
        var alpha = rand(options.alphaMin, options.alphaMax);

        //draw on canvas context
        ctx1.shadowColor = hsla(hue, saturation, lightness, alpha);
        ctx1.shadowBlur = blur;
        ctx1.beginPath();
        ctx1.arc(x, y, radius, 0, Math.PI * 2);
        ctx1.closePath();
        ctx1.fill();
      }

      parts.length = 0; //clear parts array
      for (
        var i = 0;
        i < Math.floor((canvasWidth + canvasHeight) * 0.03);
        i++
      ) {
        parts.push({
          radius: rand(1, sizeBase * 0.03),
          x: rand(0, canvasWidth),
          y: rand(0, canvasHeight),
          angle: rand(0, Math.PI * 2),
          vel: rand(0.1, 0.5),
          tick: rand(0, 10000),
        });
      }
    }

    function resize() {
      canvasWidth = c1.width = c2.width = parentEl.offsetWidth;
      canvasHeight = c1.height = c2.height = parentEl.offsetHeight;
    }

    function animate() {
      window.requestAnimationFrame(animate);

      ctx2.clearRect(0, 0, canvasWidth, canvasHeight);
      ctx2.globalCompositeOperation = "source-over";
      ctx2.shadowBlur = 0;
      ctx2.drawImage(c1, 0, 0); //copy canvas 1 to canvas 2
      ctx2.globalCompositeOperation = "lighter";

      var i = parts.length;
      ctx2.shadowBlur = 15;
      ctx2.shadowColor = "#fff";
      while (i--) {
        var part = parts[i];

        part.x += Math.cos(part.angle) * part.vel;
        part.y += Math.sin(part.angle) * part.vel;
        part.angle += rand(-0.05, 0.05);

        ctx2.beginPath();
        ctx2.arc(part.x, part.y, part.radius, 0, Math.PI * 2);
        var alpha = 0.075 + Math.cos(part.tick * 0.02) * 0.05;
        ctx2.fillStyle = hsla(0, 0, 100, alpha);
        ctx2.fill();

        //make sure particles stay within canvas bounds
        if (part.x - part.radius > canvasWidth) {
          part.x = -part.radius;
        }
        if (part.x + part.radius < 0) {
          part.x = canvasWidth + part.radius;
        }
        if (part.y - part.radius > canvasHeight) {
          part.y = -part.radius;
        }
        if (part.y + part.radius < 0) {
          part.y = canvasHeight + part.radius;
        }

        part.tick++;
      }
    }

    function init() {
      //create canvases
      c1 = createCanvas();
      c2 = createCanvas();
      ctx1 = c1.getContext("2d");
      ctx2 = c2.getContext("2d");
      parentEl = document.getElementById("wrapper");
      parentEl.insertBefore(c2, parentEl.firstChild);
      parentEl.insertBefore(c1, c2);

      resize();
      createAnimation();
      animate();

      window.addEventListener(
        "resize",
        debounce(function () {
          resize();
          createAnimation();
        }, 250)
      );
    }

    init();
  </script>
</html>
